Armed with a pocketful of one-liners that kept his audience chuckling, President Reagan got a chance Saturday night to tweak the fourth estate at the annual White House Correspondent's Association Dinner.

"You don't know how happy we are to see all of you here tonight, because while you're here you can't be listening to all those unnamed authoritative sources in the White House," deadpanned the president to a crowd that included Nancy Reagan, hundreds of journalists, several Cabinet members, White House aides and a lot of formers.

"And since this administration is determined to be open and aboveboard, I want you to know that we are installing a tape system in the Oval Office--adhesive tape right across the mouth."

Some of his other quips:

* "Incidentally, did you see our friend Lyn Nofziger on '60 Minutes' the other night? They said that he was now an influence peddler. That's ridiculous. He just dresses like a peddler."

* "I hope Leonid Brezhnev can come to New York in June. I want him to see our free press in action. I want him to see that contrast between a free press and a controlled press, that's the only thing he knows. They can't criticize him, they can't take potshots, write insulting stories about him when he takes a day off to go swimming . . . On the other hand, there's something to be said for a controlled press . . . "

* "No I don't mean that. You just keep on seeking the truth and I'll keep on telling it, even though you don't recognize it."

The clamor, kissing and serious drinking in the vast Washington Hilton ballroom was a reunion for two of Washington's elitist industries: the government and the press. Cocktail receptions and post-dinner parties abounded in suites throughout the hotel.

"It's like an adult prom," said Time correspondent Maureen Dowd.

Reagan couldn't make last year's dinner because he was recovering from the attempt on his life. This was also White House Press Secretary Jim Brady's first Correspondent's Association Dinner. He sat quietly in a wheelchair at the Chicago Tribune's table with friends lining up to see him.

"I was a little worried about his coming tonight, I thought it would be too much for him," said his wife, arah. "But he was determined to come and see his old friends." Brady received a long standing ovation when he was introduced.

The indoor sport of table-hopping was played with vigor. What better time for a reporter to buttonhole an administration official who has not been returning phone calls.

Victor Ostrowidzki of Hearst Newspapers tried. But White House Chief of Staff James Baker would have none of it.

"What was he asking you?" Nancy Reynolds inquired of Baker a minute later.

"He wanted to talk about Nixon's role in the administration," drawled Baker. "I'm not going to talk about that. If Nixon talks to the president on the phone that's a private matter."

Every year, news organizations start inviting guests months before the dinner. Competition is fierce. And cachet is measured by a guest's access to the president. Presidential Counselor Edwin Meese said he was invited by "quite a few people." But the association's president, Clifford Evans, had pinned Meese down last September. "So now I'm trying to go to as many parties as I can," said Meese, roaming in and out of suites.

British Ambassador Sir Nicholas Henderson--a rare guest at large parties since the Falkland Islands crisis--was the guest of the London Times. "I came late because of work and I'll probably leave early," Henderson said. "It's a dangerous situation and we're prepared to face up," he said when asked of the possibility of war with Argentina. "We have committed no act of aggression."

White House spokesmen Larry Speakes and David Gergen would have been considered catches, but they were involved in a separate arrangement. They were at Table 4 with former White House press secretaries, from the Truman through Reagan administrations, as guests of the White House Correspondent's Association.

"So far everything's been fine," said Jimmy Carter's press spokesman Jody Powell. "I expected that the table would be pelted with garbage--banana peels and lemon rinds. But everyone's been nice."

"The best advice I got was from Ron Nessen Gerald Ford's press secretary ," Speakes said. "He told me to make sure to always go to the bathroom before a briefing . . . because you're gonna be out there forever."